Superconductive properties in mercury were first discovered by H. Kamerlingh Onnes in 1911. Onnes had discovered a way to liquefy helium at low temperatures. To manipulate these low temperatures, he began to experiment with the electrical properties of metals. He found that at temperatures below around about 4 Kelvin, mercury's resistivity abruptly decreased to zero. With no resistivity, a material can conduct current forever, so he called his discovery superconductivity.

In 1933, Walther Meissner and Robert Ochsenfeld found that superconductors repel magnetic fields. This finding means that superconductors can experience perfect diamagnetism. The complete exclusion of magnetic flux from the interior is known as the Meissner Effect.

Up until 1957, the reason superconductivity occurred was not understood. John Bardeen, Leon Cooper, and John Schrieffer proposed the BCS theory of superconductivity. They received a Nobel Peace Prize for their theory in 1972. BCS theory is still used to explain the behavior of superconductors at low temperatures.